i have looked and searched for how to's on the site and only found ones on newer truck, just wondering what it will take to do one on my 97 auto? i would like to know what wires to wire and what colors to what, and anything else i might need to know to do this mod, thanks alot!

 

Do a search for "mystery switch" here, you'll get lots of hits. Also, here is the instructions from TST's website: http://www.tstproducts.com/Torque%20...p%20Switch.pdf

 

That .35 cent switch is responsible for many thousands of dollars in transmission repairs... use it wisely.

 

okay thanks for the link, that was really helpful, and i searched for mysyert switch and got some cool facts, but all i need to know now is how and when should i use this? i will be pulling a small 24 foot camp trailer here soon and want to get it done before i go on the trip, please help! and tell me how to use it correctly so i wont break stuff

 

Just don't let the transmission shift with lockup forced by the switch if has stock shafts.

 

this is VERY true! I have a buddy who thought it was cool to let his truck downshift with the TC locked when he layed on it at a low rpm....... he now has a very broken trans in his cummins

 

So shifting up through the gears with the TC locked is OK? (I am not well versed on the workings of an auto trans, so please excuse my ignorance)

Rob

 

i just got it installed, and i love it! it works great!

 

Could someone tell him when/when not to use it? I have read many post about it and its still a mystery to me, he he get it?
Floyd

 

I Use Mine After Like 30 Mph And Once I Hit The Brakes I Turn It Off, And It Works Good!

 

The easiest on the tranny would be to never let it shift up or down with TC lock forced by the switch. I imagine the up shifts are harder on the shafts since you are applying power. Probably the 1-2 shift would be the hardest on it followed by the 2-3 then 3-OD due to the mechanical advantage the lower gears have.

If your pulling a grade that you need a lower gear for (3rd or 2nd) then either lockout OD or downshift to 2nd (so it stays in that gear), then hit the lockup switch. When you need to upshift then unlock the TC, change to a higher gear then relock the TC.

Just my opinion, I personally would hate to break a shaft while towing a trailer a long way from home.

 

I've just about given up hooking one up. I've tried every way possible (except using relays) including what Dusty (HTS) and still can't get it to work. I'm trying one more combo and if that don't work, I'm quiting before I tear something up.

 

go to 4x4wire.com click on fullsize trucks, tech archives and tc lockup switch

 

Good thread........However, it says nothing about adding a resistor in line, and it states that this mod will not work on '99-up trucks. Anyone here know this to be true? Could the addition of the resistor to the ground wire be the key to making this mod work on '99 and later rigs?

Rob

 

The resistor is to allow the continued use of the relay and to keep from setting codes. If you leave the relay in without the the resistor the trans will go into limp mode. '99 and up rigs wire the same way. All you are doing is grounding the orange/black trace wire which is the way it locks the converter.

If it locks on it's own and won't lock with the switch the only thing I can think to cause that would be no continuity in the switched circuit.